1. Field of the Invention
The present invention relates to an unevenness detecting device detecting the processed state of a processed groove such as a laser-processed groove, a cut groove, or the like processed in a workpiece such as a wafer or the like or the state of unevenness of traces of grinding on a ground workpiece surface.
2. Description of the Related Art
In a semiconductor device manufacturing process, a plurality of regions are partitioned by scheduled division lines arranged in a lattice manner on the top surface of a wafer having substantially the shape of a disk, and devices such as ICs, LSIs, or the like are formed in the partitioned regions. Then, after the undersurface of the wafer is ground to form the wafer with a predetermined thickness, the regions in which the devices are formed are divided from each other by cutting the wafer along the scheduled division lines. The individual devices are thus manufactured.
A grinding device for grinding the undersurface of a wafer includes a chuck table holding the wafer, grinding means including a grinding wheel grinding the wafer held on the chuck table, thickness measuring means for measuring the thickness of the wafer, and the like (see for example Japanese Patent Laid-Open No. 2002-319559).
In addition, the above-described division along the scheduled division lines of the wafer is performed by a cutting device or a laser processing device. The cutting device includes a chuck table holding a wafer, cutting means including a cutting blade cutting the wafer held on the chuck table, imaging means for detecting scheduled division lines formed on the wafer held on the chuck table, and the like (see for example Japanese Patent Laid-Open No. Hei 7-45556).
In addition, the laser processing device includes a chuck table holding a wafer, laser beam irradiating means for irradiating the wafer held on the chuck table with a laser beam, imaging means for detecting scheduled division lines formed on the wafer held on the chuck table, and the like (see for example Japanese Patent Laid-Open No. 2008-12566).
The cutting device or the laser processing device detects the state of a cut groove or the state of a laser-processed groove by imaging the cut groove or the laser-processed groove by the imaging means so that processing conditions can be adjusted (see for example Japanese Patent Laid-Open No. Hei 5-326700).